As electrophotographic image forming apparatuses, there are known printers in which photosensitive members and a developing unit are contained in an apparatus main body, the photosensitive members carry developer images, and the developing unit feeds developers to the photosensitive members.
For example, there is known a printer in which an opening and a supporting member are provided at the top of an apparatus main body, wherein the opening is for maintaining photosensitive members and a developing unit, and wherein the supporting member is for opening and closing the opening.
In this related-art printer, the supporting member closes the opening when the supporting member is placed close to the apparatus main body (an adjacent state), and the supporting member opens the opening when the supporting member is placed away from the apparatus main body (a distant state).
Further, the related-art printer includes an arm that rises with respect to the apparatus main body so as to hold the supporting member in the distant state, and an arm spring that presses the arm so as to raise the arm.